1. Field of the Invention
The present invention relates to eyeglasses used as, for example, sunglasses and goggles, etc.
2. Description of the Prior Art
A pair of eyeglasses which has been conventionally used consists of, as shown in FIG. 10, a main body 30 (single-lens structure) and a pair of left and right side temples 32 attached to the main body 30 through frames 31 fixed to left and right side upper ends of the main body 30. In the conventional eyeglasses of this type, the lens is desirably curved sharply so as to prevent wind and light from entering from the sides when used in various sporting events such as a bicycle event.
In addition, according to the conventional eyeglasses of this type, as shown in FIG. 11, engagement shaft holes 33 are provided at the frames 31, and protrusions 34 provided at forked front end portions of the temples 32 are engaged with the shaft holes 33. Due to this, the temple 32 contacts the outer end 35 of the frame 31, thus being prevented from further rotating outward. As a result, if the temple 32 is forced to be opened further, the main body 30 is disadvantageously deformed and its original curved-shape is damaged. In addition, if the eyeglass main body 30 is curved more sharply, the opening angle of the temple 32 becomes narrower. As a result, the temple 32 disadvantageously pinches the head of a user and the eyeglasses become uncomfortable to wear.
Under the circumstances, according to the conventional eyeglasses, the sphere of the main body 30 is normally about 6 curves and it has been difficult to merchandise ones having a sphere curved more sharply. By the 6-curve sphere, it means a sphere having a radius of curvature R1 (mm) thereof (or front surface) set at: EQU R1=(N-1).times.100/D[D=6]
where N is the index of refraction of material.